Sanguinaria canadensis is known as Bloodroot, Puccoon, Tetterwort, etc and is an herb native to North America. The plant and its juices have been used for various purposes during pre-history as well as written history. It has been used as a natural historic folk remedy medicine. The plant has been generally used whole, either undried (fresh) or dried. The usual procedure is to powder the dried plant and mix it with a carrier. This folk remedy has been tried for such things as asthma, bronchitis, dysentery, ringworm, and a substantial list of other ailments.
Sanguinarine, chelerythrine and other benzophenanthridine alkaloids are known materials in Bloodroot and recovery of these materials involve procedures which include one or more chromatographic separation steps. However, this is not feasible for commercial purposes of producing an innocuous extract from the rhizome of bloodroot.
The use of an extract of Sanguinaria canadensis as an ingredient in oral cleansing preparations, in particular, toothpaste, is disclosed in U.S. Pat. No. 4,145,412.
This extract is produced by treating a finely cut or ground bloodroot with an organic solvent, such as methanol. The bloodroot is thoroughly stirred with several volumes of the solvent, and is maintained in the solvent for 24 hours or more, at a temperature of about 60.degree. C. Subsequently, the solution is filtered and the methanol is evaporated. The residue is dissolved in chloroform, treated with concentrated hydrochloric acid, filtered and then dried. This dried extract is generally taken up in warm glycerine (65.degree. C.) for mixing with a carrier.
The extract, when combined with a dentifrice or oral care product is an excellent breath freshener, and also an anti-plaque and anti-gingivitis agent; however, it is bount or sorbed by abrasives such as dicalcium phosphate and is shifted to the pseudo base form at pH's greater than 6.0. The normal pH's of dicalcium phosphate containing dentifrices is alkaline. Zinc chloride may be added to di-calcium phosphates to lower the pH. Zinc chloride has also been used in dentifrices for their anti-plaque properties; however, zinc chloride imparts an acrid mouth taste. Typical zinc compounds and derivatives used in dental compositions are set forth in U.S. Pat. No. 4,325,939.
It is therefore highly desirable to provide a dentifrice containing an extract of Sanguinarine Canadensis L. of improved stability, with increased uptake in dental plaque of sanguinarine chloride, without the use of a di-calcium phosphate or other alkaline abrasives, and zinc chloride.